1. Field of the Invention
The present invention relates to security railings for balconies, stairs, and the like and more particularly to a railing of which at least the outer surface which is exposed to the elements is of plastics material, and which will meet building codes.
With the present trend toward multistory condominium and apartment buildings having balconies, there is a need for a security railing formed at least on the surface exposed to the elements, from non-corrosive materials. It has been found that metallic security railings which have been constructed from iron, steel, aluminium or the like have a short life in buildings exposed to polluted air and for buildings in coastal areas exposed to the corrosive effect of the salt water atmosphere. To maintain such metallic security railings in safe condition, continuous maintenance is required for removing rust and corrosion, and for refinishing of the railings. Where such maintenance is neglected, such railings can quickly become unsafe and dangerous.
2. Description of Related Art
There have been attempts in the prior art to develop reinforced non-metallic structures suitable for railings. For example, in U.S. Pat. No. 4,181,764 to Totten, a rail is disclosed having a wooden core with a weather and abrasion resistant outer coating. However, a plurality of valve means must be provided for releasing vapour from the core yet preventing passage of water into the core. Furthermore, the strength of the Totten rail is determined by the wood core. To obtain the necessary strength for a building security railing, it is considered that the resulting structure would be too bulky and unattractive. Murphy in U.S. Pat. No. 3,957,250 teaches a fence post fabricated from tubular plastic material and filled with semi-rigid or rigid foam for additional strength. However, the posts appear to be suitable only for stringing of wire fencing. The U.S. Pat. No. 4,053,140 to Clemens, et al shows a non-corrosive plastic handrail system designed for use in industrial applications along stairways, platforms, and the like to eliminate the corrosion problems due to electric currents and fields as well as corrosive environments. The strength of the handrail system described depends upon the use of a special thermosetting resin in which high tensile strength reinforcing fibres have been incorporated as taught by U.S. Pat. No. 3,859,409. Such specialised material is expensive and the patent does not disclose any testing of strength to determine if the material would satisfy building codes for balcony railings in apartment buildings and the like.
It has furthermore been proposed in U.S. Pat. No. 4,461,461 to Lee Caron to provide a security railing formed entirely from polyvinyl chloride pipe having a novel laminated structure which has the advantages of being lightweight, low cost, and non-corrosive. The railing disclosed in said Caron patent will withstand significant deformation yet will return to its original shape when the load is removed.
In the Caron patent a balcony railing or the like is constructed which has a normal appearance. For example, there is a plurality of upright posts which may be attached to the building floor in any conventional manner such as by flanges, anchoring in the concrete, or the like. It is preferred to anchor a steel pipe or bar into a concrete deck with the post placed over the pipe. A top rail is provided coupled to the vertical posts by suitable T or cross couplings. Similarly, a lower rail is provided coupled to the vertical posts by cross couplings. Disposed between the upper and lower posts is a plurality of smaller rail elements closely spaced in a conventional pattern.
In accordance with the Caron invention, the top rail sections and the vertical posts are formed by laminating two polyvinyl chloride (PVC) pipes. For example, the outside pipe may be a schedule 40 PVC pipe having a nominal 11/2 inch diameter which is actually 1.99 outside diameter and 1.66 inside diameter. An inner PVC pipe formed from schedule 80 PVC is inserted through the outer pipe. The outer diameter of the inside pipe is 1.66 inches and the inside diameter 1.278 inches. As may be recognized, the inside pipe forms a snug fit into the outside pipe to thereby form a laminated rail having both strength and flexibility. It may be seen that a load placed on the laminated rail will cause a deflection and the inner pipe may move relative to the outer pipe to prevent excessive stress at the point of load, yet the combination provides the required strength.
In addition to the laminated construction of the top rail, Caron proposes that similar laminated PVC pipes be utilised for the posts. He suggests that the lower rail does not require lamination although he states that it will be obvious that the laminated rail may also be used as the lower rail. Otherwise, schedule 40 11/2 inch PVC pipe may be used.
The vertical elements between the posts may be 1/2 inch diameter schedule 80 PVC pipes spaced about 6 and installed in holes drilled along the top and bottom rails. It has been found that a spacing of posts of about 4 feet provides the required strength.
The PVC pipe utilized to form the rails may be obtained in a variety of finishes and colours. Thus, the security railing can be made very attractive and requires essentially no maintenance.
A typical railing section disclosed by Caron was tested under Southern Building Code, Section 1204, Special Load 1204.2-Railing. The railing was anchored in concrete in a horizontal position. The railing was loaded to 50 pounds per linear foot and withstood the load with a maximum downward deflection of 6 inches. After removing the load, the railing assumed its original shape with no permanent deformation. The testing laboratory reported that the security railing met the applicable code specifications.
The strength and safety features of the Caron railing is further shown by a report from the testing laboratory which noted that during the 50 pound per linear foot load test, the anchoring of the jig used failed. This caused a 1600 pound load to be catapulted unto the railing. The laboratory reported that the railing received the entire weight of this load along the full length of the rail about the midsection thereof. This excessive load bent the rail at approximately a 40.degree. angle but with no structural damage thereto. Once the load was removed, the railing sprung back to its original shape.